Possibly stripping spark plug hole (1 Viewer)

[MrClean]

I've had a starting issue and so I took my plugs out to have a look at them. They all came out easy and looked fine. Went to put them back in and 3 of the 4 went in fine. Last one near the firewall is not going in. I cleaned the spark plug hole out and attempted to use a spark plug thread chaser while lubricating with WD40. Very hard to see if I'm going in straight and after just a little bit of screwing in and inspection, I see shavings. Before I go too far, any suggestions? What are my options if it gets completely stripped? 20R motor in '79 pickup. Thanks.

 

[pappy]

New head. One year ago my #4 plug blew out of the head on a road trip. Common for some reason on #4. Local dealer tried to helicoil the hole, but it didn't hold. My solution was to replace the head using a LCE product.

 

[MrClean]

Thanks for the reply Pappy. I think only the top portion of the threads are damaged. Did a little research and I'm going to try this tool.

 

[chesshircat]

I've had a starting issue and so I took my plugs out to have a look at them. They all came out easy and looked fine. Went to put them back in and 3 of the 4 went in fine. Last one near the firewall is not going in. I cleaned the spark plug hole out and attempted to use a spark plug thread chaser while lubricating with WD40. Very hard to see if I'm going in straight and after just a little bit of screwing in and inspection, I see shavings. Before I go too far, any suggestions? What are my options if it gets completely stripped? 20R motor in '79 pickup. Thanks.

I used a time-sert on my tacoma. worked great, did it withthe head on the engine.

 

[KLF]

New head.

I think this is a little drastic. Plenty of stripped spark plug holes have been repaired with the head in place and worked just fine.

 

[pappy]

I think this is a little drastic. Plenty of stripped spark plug holes have been repaired with the head in place and worked just fine.

Did you miss the part where the dealer attempted a repair and it failed.

 

[KLF]

Did you miss the part where the dealer attempted a repair and it failed.

In the original post? No I don't see it there, I just read it again. He ran a thread chaser down and it didn't seem to help.

???

 

[pappy]

In the original post? No I don't see it there, I just read it again. He ran a thread chaser down and it didn't seem to help.

???

Sorry, I thought you were questioning my replacement head. As I said:

Local dealer tried to helicoil the hole, but it didn't hold. My solution was to replace the head using a LCE product.

 

[Pin_Head]

Don’t use a helicoil. Use a timesert spark plug insert.

 

[MrClean]

Wanted to update the thread in case someone else has this issue and is looking for options. I was able to resolve the stripped spark plug hole with this tool. It's a spark plug back tap thread repair tool and it really saved my a$$. The tap works by screwing from the inside out. Since it screws out there is less chance you will drop thread shavings in the cylinder. I basically followed the directions and ran the tool through 5 or 6 times, expanded it a little more each time and being very patient with it. When I was done I could screw in/out the tool with my fingers. The spark plug screwed right in after that.

 

[snaggletto]

I used this same tool on my 22re head. I had a totally cross threaded hole from a previous owner. Worked great. Definitely try it before thread inserts or re tapping.